Refrigerating apparatus



REFRIGERAT ING APPARATUS Filed June 26, 1937 2 Sheets-Sheet 1 @Ki QA."

ATTORNEY Nov. s, 1940. F. w. HARTMAN 2,220,447

REFRIGERATING APPARATUS Filed June 26, 1937 '2 Sheets-Sheet 2 ATTORNEY Patented Nov. 5, 1940 2,220,447 REFRJGERATING APPARATS Frank W. Hartman, Detroit, Mich., assigner to Henry Ford Hospital, Detroit, Mich., a corpora tion of Michigan Application June ze, 1937', serial No. 150,594 f 14 claims. (ci. 12s-191') s PATENT oFFlcE The present invention relates to the art of refrigeration of tents and particularly to refriger- -ating and supplying oxygen to oxygen tents. One of the objects of the present invention is to provideran improved method of and apparatus for refrigerating tents by cooling the circulating medium by a liquid low enough in temperature so that the noxious gas, given olf by the occupant o f the tent, is condensed by the liquid.

Another, object of the invention is to cause the circulating medium of the tent to ow in heat exchange relation with liquid air and liquid oxygen and to cause the gas from these liquids to be circulated in the tent. l

In carrying out the foregoing object it is a further object to control the relative rate of vaporization of the liquid air and liquid oxygen.

A further object is to provide a heat absorber of a relatively highertemperature than the liquid refrigerant but which is maintained at'a temperature below the dew point of the moisture in the Vcirculating medium soas to condense the moisture from the circulating medium, and to position this heat absorber so that the circulating medium flowing toward the liquid refrigerant first comes in contactv with the heat absorber.

Itis a still further object of the present invention to yieldingly connect the tent with therefrigerated cabinet. I

Other and further objects and advantages will be apparent from the following description, reference being had to the accompanying drawings wherein a preferred form of embodiment of the present invention is-clearly shown.

In the drawings: y

Fig. 1 is a view in perspective showing the invention as applied vto a bed, a part of the tent being cut away;

Fig. 2 is a'sectional view of the cooling apparatus, the section being taken'on line 2-2 of Fig. 1; l

Fig. 3 is a side view of the cooler with the door thereof removed; the tent is shown attached and a part of the tentis cut away; a receptacle is shownin longitudinal cross section;

Fig. 41s a front view of the cooler with th door partly'open;

Fig.l 5 is a fragmentary sectional view of 'the lower front part' of the coolershowing the drip 4trough and drain, the section being taken on line5--5ofFig.4;

Fig.'6 is a. detailed View of one of the valves and the mechanism for actuating the same;

Fig. 7. is a perspective viewv of one of the heat conductors which straddles the rim of a refrigerant receptacle; and 1 1 Fig. 8 is a front view of a preferred form of the invention.

Referringto the drawings, the present inven- 5 tion 'is illustrated with a bed to which it is particularly applicable. Referring to the drawings the bed is shown at 20 carrying a mattress 2l and ,other bedding 22. The cooler 24'is preferably placed in back of the head 25 of the bed 20. 10 The4 cooler comprises an insulated cabinet 21 having an inner metal lining 28 and' an insulated side door 29. This door is preferably hinged at the bottom on hinges 30 and is latched in position by a latch 3l at the top. 'I'he cabinet 21 is 16 supported by a telescoping type stand 33 which -'is adjustably set at the desired heightby a set screw 34. 'I'he stand 33 is provided with two relatively short legs 35 and a relatively long front 1eg 3s, each of which is supported by a. rubber 20' tired wheel 31. The cabinet 21 is hinged to the stand 33 vby anl adjustable clamp 38 which is. tightened. in position by a screw 39. In this manner the cabinet 21 can be tilted sidewise. The front 4| of the cabinet 24 carries a wooden 25 plate 42 having a sheet metal face 43. 'I'he front 4I of the cabinet 2 1 li's also provided with four sleeved opening 45, 46, 41 and 48. The sleeve 50 Yof each is preferably formed of insulating material. Openings and 46 are disposed above 30 openings 41 and 48 and the former provide inlet openings to the cabinet while the latter provide outlet openings therefor.

A hairpin shaped support 52 includes inwardly and downwardly extending projections 53,. 35

These projections 53 are suitably carried by thel plate 43 so that -the support 52 extends forwardly and when in the position shown, projects over the head portion of the bed. This support 52 carries a tenty 53'. This tent is' preferably formed 40 of thin transparent rubber or rubberized material. The bottom of the tent is open so that it can be placed about the patient in the bed and the loweredges thereof are then ltucked under the bedding so as to substantially seal the bot- 45 tom of the tent. 'I'he rear of the tent is formed with a circular shaped opening arranged to t over the plate 42 on thek front of the cabinet.

This plate 42 is provided with agroo've 54 and a. resilient band' 55, preferably formed off"rubber 50 the bedding, form means for providing a closed circulatory system. l

When it is desirable to supply oxygen to the patient, I prefer to employ liquid voxygenifJ This liquid oxygen will be placed in the interiorof the liquid. The cooled air will then pass through the` openings 41 and 48 to the interior of the tent.

The liquid oxygen receptacle being atflower temperature than the CO2 gas, given offj'by the patient, will cause condensing and freezing' of the CO2 on the receptacle. Due to the fact thaty cold gas passes adjacent face 43 on the `front of the cabinet, it will be cooled to below the dew point of the moisture in the gas and therefore moisture will be condensed on the face 43. A trough 56 is carried on the bottom of the face`43 for catching the drip and this condensate is drained from the trough 56 by a tube 51 vextending to the interior of the tent.-

It is desirable to supply air as well as oxygen to the patient and in order to accomplish this I also place liquid air in the cabinet 21. The gas given 01T by the liquid air is mixed with the oxygen gas and this mixture circulates as previously described. The liquid oxygen and the liquid air are contained in open top receptacles of the vacuum type. The liquid air receptacle is shown at 59 and the oxygen receptacle is lshown at 60. The liquid air being colder than the liquid oxy- `gen-normallywould tend to boil oi faster than the liquid oxygen and in order to control the boiling off of these liquids and to maintain the desired percentage of oxygen in the gas mixture, I control the amount of heat conducted to the 'liquids as will be explained hereinafter. Strips of metal 62 extend into the liquids for co-nducting heat thereto and in 'order to maintain a relative ly large heat absorbing surface having a relatively small temperature gradient between different parts thereof, the strips are placed in intimate heat exchange relation with the lining 28 of the refrigerated cabinet. One of these heat conducting strips 62 is shown in Fig. 7. These strips 62 are adapted to straddle the upper part of the receptacles 59 and 6U and the lower parts of the inside legs 63 thereof are bent to conform to the rounded shape of the receptacles. The outside legs 64'of strips 62 are placed against the lining 28. The heat from the circulating medium will be absorbed by the lining and conducted from the strip 62 to the liquid. It will of course be understood that the receptacles 59. and are colder than the lining 28 and that heat will be'absorbed 'directly by the receptacle.

A large part of the CO2 gas which is condensed in the cabinet 21 will freeze on the metal covers of receptacles 59 and'. This solid CO2 is preferably removed at the time that the receptacles are refilled. In order to control the oxygen content `of the gas, the relative rate of vaporization of the liquid air and liquid oxygen is controlled by controlling the heat exchange between the liq- -lnection with the liquid oxygen receptacle 60 and one strip should be used in connection with the liquid air receptacle 58. It will of course be understood that this;4 relationship must necessarily vary in accordance with factors which are different from those specifically shown in the present application.

Itffis desirable to control the rate of circulation within the system and for this purpose I provide valves 66, 61 68 and 69 for controlling-'the iow of ggas through passages 45, 46, 41 and 48 respectively.` Ihese valves are operated in pairs. That isj'wlien valve 66 is being moved toward open or closed position, valve 69 will be moved toward openffor closed position. Valves 61 and 68 are also #coupled with one another. Each valve is connected by a link 1I to a crank 12, of a crankshaft 13. The cranks are located in the respectivepassages and both cranks extend to the exteriorof the cabinet and are there provided with handles 14 for actuating the same. In this manner a close regulation can be maintained of the circulation of gas so that they temperature Within the tent can be maintained 8 or 10 F. below room temperature. Preferably only. one set of valves are provided; namely, valves 68 and 69 which control the flow of gasfrom the cooler to thetent, the openings 45 and 46 being maintained so that the flow of gas from the tent to the cooler is not impeded.

From the foregoing it will be seen that I have provided a method and apparatus for maintaining a relatively low CO2 content of the gas in an oxygen tent. By employing liquid oxygen as an element for cooling the circulating gas and for supplying oxygen gas thereto, I have materially simplified the administration of oxygen'to the patient While at the same time maintaining a cold gas. By employing liquid air and controlling the relative rate of vaporization of the liquid air and liquid oxygen, the oxygen content of the circulating gas can be maintained substantially constant and the liquid air also provides a medium for assisting in the cooling of the gas to be inhaled and simultaneously provides a condensing surface for causing solidiflcation of the CO2 gas given off by the patient.

By controlling the flow of the gas through the valves, any desirable temperature can be maintained within the tent. I have foundthat the valves can be regulated so that the temperature within the tent can be maintained at that normally desired, 8 or 10 F. below room tempera.- ture, and suilicient circulation is maintained so that the CO2 content of the circulating gas is below 1%'.

By providing the yielding connection between the tent and the insulated cabinet 21, the tent can be pulled away from the cabinet very readily. In this manner an unruly or delirious person cannot overturn the cabinet because the yielding connection will permit the detachment of 4the tent from Athe cabinet by a slight jerk, since the resistance of the yielding connection is less than the energy required to overturn or upset the cabinet. To further safeguard against the upsetting of the cabinet, the long leg 36 is positioned at the forward side of the cabinet so that in case the cabinet is overturned, the contents thereof cannot strike the bed.

l A further advantage of the present -invention is that the entire apparatus may be placed at the It will" be understood that when the apparatus back of the bed whereby the nurse may have )access to thelsides and foot of the bed.

thehead to the foot of the bed. Inthat case the lower edges of the tent will be tucked under the extreme edges of the bedding or mattress.

While the form of embodiment of the present invention as herein disclosed constitutes a lirei'erred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which i'ollow:

I claim:

1. The method of administering oxygen to a person in an enclosure and removing the noxious gases of .respiration from circulation in the enclosure which consists in directing oxygen gas, boiling oi! from liquid oxygen, into the enclosure and directing the gases o! the enclosure. including the noxious gas given on by the respiration of the person, into heat exchange relation with the liquid oxygen to thereby cause condensation and precipitation of the noxious gas.

2. That step oi' administering oxygen to a person in an inclosure Yand removing the noxious gases of respiration from circulation which consists in directing the gases, boiling oii' from liquid oxygen and liquid air, into an enclosure, directing the gases of the enclosure, including the noxious gas given ci! by the respiration of the person, into heat exchange relation with the liquid oxygen and liquid air to thereby cause condensation and precipitation oi the noxious gas, and controlling the rate of vaporization oi' the liquidair and liquid oxygen.

3. 'Ihe method of administering oxygen to a person and removing noxious gases o! respiration of the person from circulation which consists in directing oxygen gas, boiling oi! from liquid oxygen, into the presence of the person and directing the noxious gas given oi! by the person into heat exchange relation with the liquid oxygen to thereby cause condensation and precipitation oi' the noxious gas. 4. The method of administering gas to a person which consists in directing gas boiled oil' from its liquid state, to the person. and directing noxious gas given ,oir by respiration of the person in to heat exchange relation with the boiling liquidgaswherebythecoolingeifectoitheboiling gas condenses and precipitates the noxious gas.

5. Themethoddennedinclaiml characterised by the fact that the gases are circulated due to convection.

'6. Themethod deiinedinclaimlinwhichthe rateoi'ilowofgasesiscontrolled Av. The method dennen in claim i in which gasesfromliquidairarealsodirectedintotheinclosure.

ammetheadennedinelaimimwhiehthe lgasesexhalcdllvythepcl'sonarealsobl'ought mwexchmenhupnwannqummmuhe gnsesh'omtheliinidairarealscdirectedinto inclosure.

for the inlet and outlet of a circulating medium, a tent associated with the cabinet to receive the circulating medium from the outlet and for discharging the circulating medium to the inlet, and an open receptacle containing liquid oxygen disposed within the cabinet.

10. In combination, an insulated cabinet open for the inlet and outlet of a circulating medium, a tent associated with the cabinet to receive the circulating medium from the outlet and for discharging the circulating medium to the inlet, and an open receptacle containing liquid oxygen and a receptacle containing liquid air each dispOsed within the cabinet. Y

11. In combination, an insulated cabinet open for the inlet and outlet of a circulating medium, a tent associated with the cabinet to receive the circulating medium from the outlet and for discharging the circulating medium to the inlet, an open receptacle containigliquid oxygen and a receptacle containing liquid air disposed within the cabinet, and means for controlling the relative ratel of vaporizations of the liquid airvand 12. In combination, a bed; a cabinet open for the inlet and outlet of a circulating medium, said cabinet being disposed to one side of and at a higher level than the bed; a tent support; a tent carried by the support above the bed, said tent being open at the bottom and adapted to be tucked into the bedding and being open for attachment to the cabinet about the inlet and outlet of the' cabinet; and means for yieldingly and sealingly attaching the tent to the cabinet.

13. In combination, a bed; a cabinet open for the inlet and outlet of a circulating medium, said cabinet being disposed to one side of and/at a higher level than the bed; a tent support; a tent carried by the support above the bed, said tent being open at the bottom and adapted to be tucked into the bedding and being open for attachment to the cabinet about the inlet and outlet of the cabinet; a shoulder surrounding the inlet and outlet of the cabinet: and a resilientV band for yieldingly holding the tent against the shoulder.

14. The method of removing noxious gases and- Yr FRANK W. HA'RTMAN'. 

